Turkey calls fall into three broad classifications, friction calls, diaphragm calls, and trumpet calls. Friction calls produce an audible sound when a striker is pushed or rubbed along the surface of their friction plate or sounder board. For example, U.S. Pat. Nos. 1,034,307 to Saunders, 3,367,064 to Anthony, et al., 4,003,159 to Piper, and 4,904,221 to Taylor, disclose friction calls and teach pushing or rubbing a striker across the surface of a hand held friction plate to produce an audible sound that simulates gobbler and hen turkey sounds; the sounds being described as "yelps and clucks." Such hand held friction plates are problematic for users trying to create sounds that imitate wild turkey calls. They are especially problematic for beginners having low levels of calling and hunting skills. This is because the user must grasp the friction plate in one hand while they push or rub a striker along the surface of the friction plate. This procedure is clearly illustrated in the different drawing figures shown in the Saunders, Anthony, et al., and Taylor patents. Grasping a friction call, as taught in the past tends to dampen the acoustic vibrations that are created when a striker is rubbed across the friction surface of the call. Although skilled callers know how to cup the call in their hand to lessen such dampening effects, less skilled users tend to produce distorted and ineffective turkey calls when using such devices.
Such sound dampening problems have been somewhat overcome through the development and manufacture of hand held box type friction calls. Hand held box type friction calls include a friction plate or sounder board that is attached, either internal or external to the box structure, in a fashion that isolates the friction plate from the user's handgrip when the friction plate is rubbed by a striker to generate a simulated turkey sound. Examples of such past hand held friction call devices are disclosed in U.S. Pat. Nos. 1,449,756 to Jackson, 2,643,483 to Walker, 2,720,054 to Grazier, 4,041,639 to Funk, 4,310,986 to Jacobs, 4,606,733 to Willis, 4,648,852 to Wingate, 5,066,260 to Linder, and 5,484,319 to Battey. As mentioned above, past box type friction calls attempt to overcome dampening problems by isolating the sound generating surface from the user's hand. However, the friction calls that are available on today's market tend to have one or more of the following problems. First, the sound vibrations continue to be somewhat dampened when a user grasps the flat-sided frame of box 10 as clearly illustrated in FIG. 2 of the Willis patent. Such flat construction prevents the sound box from vibrating and reduces volume and tone quality when held tightly in a user's hand. Second, today's state-of-the-art friction calls limit the user to a single basic turkey sound pattern. This requires a hunter to carry more than one turkey call if he or she desires to simulate a selection of different turkey sounds. Third, some past friction calls securely fasten all four sides of the friction plate, or sounder board, to the frame of the box. This limits sounder board flexibility and reduces vibrational response to the striker being rubbed across its friction surface. Fourth, some friction calls house the friction surface deep within an interior chamber of the box. This enclosed type of construction traps sound vibrations within the sound chamber and reduces volume and tone quality. Finally, friction calls of the past fail to provide the user with a sounder board that makes it easy to produce the higher pitched calls; yelps, clucks, etc., of young birds. Such higher pitched sounds are particularly important during the fall season when a hunter scatters a flock of turkeys. Scattered birds can be more easily called back by imitating high-pitched sounds of a young turkey. Such high pitched sounds were not easily available to hunters, photographers, and the like using friction calls of the past.